REV - CLXL - Vol. 45 (2023)
Permanent URI for this collectionhttps://hdl.handle.net/2183/34631
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Item Characterization of Joint Mortars and Pavements from the Roman Site of A Ciadella (NW Spain)(Universidade da Coruña, Servizo de Publicacións, 2023-12-22) Alonso-Villar, Enrique Manuel; Rivas Brea, Teresa; Fernández Fernández, Adolfo; Lago Cerviño, Marta; Rodríguez Nóvoa, Alba Antía; Valle Abad, Patricia[Abstract] The results of the mineralogical and textural characterization of joint mortars and pavement samples collected at the Roman site of A Ciadella (Galicia, NW Spain) are presented. The results indicate that these are earth mortars whose most likely origin could be sub-surface horizons from nearby soils, considering the mineralogical similarity between the inherited minerals detected in the mortars and the mineralogy of the rocks in the area. No lime has been detected in any mortar. The textural analysis confirms a poor pre-treatment of the soil samples used as raw material. In the pavement samples analysed, the existence of a kaolinite-rich surface layer, probably applied deliberately on the surface, stands out.Item La investigación gallega en la aplicación de la tecnología láser para la limpieza de patrimonio cultural material: estrategias del pasado y del futuro(Universidade da Coruña, Servizo de Publicacións, 2023-12-22) Pozo Antonio, José Santiago; Rivas Brea, Teresa; Ramil, Alberto; López, Ana[Abstract] The cleaning of cultural heritage elements is essential to ensure the durability and transmission of our cultural and artistic legacy. In Galicia, the importance of our stone-built heritage reflects the skill of our masters and artisans and is a symbol of our strength as a community. The difficulty involved in cleaning polymineralic stones such as granites, schists, etc. used on these artworks justifies the need to carry out detailed research on the effectiveness of different cleaning methods, considering both the degree of extraction of the undesirable substance (crust, graffiti, biological colonization, etc.) and the side effects that such cleaning may cause, such as mineral extraction, chromatic changes, etc. For this reason, a group of researchers from the University of Vigo and the University of A Coruña have been working together for 13 years to optimize the application of laser technology as a cleaning tool for these stones. This physical method allows cleaning to be achieved in a selective, gradual, and respectful way with the environment and the workers’ health. A sustainable cleaning method is therefore possible. In addition to the innovative use of lasers to clean heritage polymineralic stones, this Galician research group made progress in this area with the simultaneous application of wavelengths (infrared-1064 nm and ultraviolet-355 nm) and the sequential combination of laser with chemical and mechanical cleaning procedures. These strategies have made it possible to reach high levels of extraction and reduce side effects thanks to the reduction of applied fluence levels.Item The Origin, Age, and Conservation, of an ‘Elevated Platform’, Yarwondutta Rock, North-Western Eyre Peninsula, South Australia(Universidade da Coruña, Servizo de Publicacións, 2023-12-22) Twidale, C. R.[Abstract] Yarwondutta Rock is a dimpled platform that was shaped at ground level by soil moisture but subsequently elevated, not because of local tectonism, but by the erosional lowering of the surrounding pedimented plains. Concave or flared slopes fashioned in the erstwhile piedmont were revealed during this erosional phase which took place in the earlier Pleistocene. The elevated platform is now buttressed against dissection by the calcreted surrounding pediments. It is concluded that in technical terms, Yarwondutta Rock appropriately can be referred to as an ‘elevated platform’. ‘Criticism and testing are the essence of our work.’ Remark by Herman Bondi on the occasion of Karl Popper’s 90th birthday anniversary (But with a reminder that a ‘criticism’ is an assessment or evaluation, and is neither implicitly, nor of necessity, adverse. C.R.T.).Item Análisis geoestadístico de macroelementos, microelementos y metales pesados extraídos con Mehlich-3 en una microparcela de viñedo(Universidade da Coruña, Servizo de Publicacións, 2023-12-22) Varela Vila, Irene; Cárdenas-Aguiar, Eliana; Lado, Marcos; Paz-González, Antonio; Vidal-Vázquez, Eva[Abstract] A geostatistical analysis of macroelements (P, K, Ca, Mg), microelements (Fe, Mn, Cu, Zn) and heavy metals (Cd, Cr, Ni, Pb) extracted with the solution Mehlich-3 was carried out at the microplot scale in a vineyard of the Ribeiro area, Ourense, Spain. The data set studied consisted of 80 samples collected along five transects, with 16 points per transect and a distance between neighbouring points of 0.8 m. The elements extracted with Mehlich-3 presented a spatial dependency, which was described by means of spherical models, except for Mn that fitted an exponential model. The adjusted semivariograms showed a strong spatial dependency, except for Zn and Pb, which exhibit moderate spatial dependency. Therefore, it was verified that the elements extracted with Mehlich-3 can present an important spatial variability even at small distances. The kriging maps showed important differences regarding the spatial distribution, between the zones of the microplot and between the elements studied. It has to be emphasized that the spatial distribution of cationic macronutrients (K, Ca and Mg) turned out to be highly dependent upon the position of the rows and the streets of the vineyard; in this way these three elements showed lower concentration in the surroundings of the row, which may be attributed to the withdrawal of such elements by the plant.